Thaci, a 38-year-old former guerrilla leader of ethnic-Albanian separatists, took the office Thursday after his coalition government was approved Wednesday by an 85-22 vote in the 120-deputy Kosovo parliament in Pristina, Serbia's Belgrade B92 radio reported.

Serbia's nationalist Prime Minister Vojislav Kostunica has warned he will not sign a pre-accession accord with the European Union Jan. 28 if Brussels dispatches a security mission to Kosovo.

Most of the EU's 27 countries and the United States support the independence plan, while Serbia, with support from Russia, is strongly opposing it.

Ethnic-Albanians make up 90 percent of Kosovo's population of 2 million.

The Serbian government in Belgrade asked some 100,000 Serbs living in Kosovo to boycott parliamentary elections Nov. 17 but those Serbs who disobeyed own 10 seats in the new parliament and two ministerial posts in the new government.

Leaders of Serbia and Kosovo have had two years of fruitless talks on the future status of the province. Belgrade wants to keep it an autonomous province and Pristina insists on independence.

Kosovo has been U.N.-administered territory since 1999, when NATO troops were deployed to curb ethnic conflicts.